checkout code during docker build since we need .git for versioning

Author: imrehg

.github/workflows/python.yaml

@@ -79,6 +79,11 @@ jobs:
     needs: test
     if: ${{ github.ref_type	 == 'tag'}}
     steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
       -
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
@@ -92,5 +97,6 @@ jobs:
         name: Build and push
         uses: docker/build-push-action@v3
         with:
+          context: .
           push: true
           tags: imrehg/linkhub_prometheus_exporter:latest,imrehg/linkhub_prometheus_exporter:${{github.ref_name}}